Model-based control of an elastic aircraft engine rotor with piezo stack actuators

Due to the fact that natural bending frequencies of elastic jet engine shafts lie in the speed range, passive or active damping is necessary to reduce radial rotor vibrations. In this study, a test rig with a high-speed turning rotor investigating active damping with piezo stack actuators was constructed. Additionally, a software-based model including nonlinear behaviors as the gyroscopic effect of the rotor and hysteresis of the piezo stack actuators was designed. The notable result of this study is that the rotor vibration and bearing force magnitudes could be reduced considerably by the implemented closed-loop control. This makes it possible to have a secure run-up passing the natural bending frequencies of the excited unbalanced rotor.